Evaporator for refrigerating machines



C. STEENSTRUP EVAPORATOR FOR REFRIGERATING MACHINES 2 Sheets-Sheet 1Filed Dec. 6, 1934 IY1\/T"ltOY Christian Steenstv up,

b 8. EMMA/1M1 y is tormey;

Feb 9, 1937.

Feb. 9, 1937. c. STEENSTRUP EVAPORATOR FOR REFRIGERATING MACHINES 2Sheets-Sheet 2 Filed Dec. 6, 1934 ITWVETTCOT. Christian SteenstPup,

by 6. mm His ttorney.

Patented Feb. 9, 1937 Christian Steenstrup, Schnectady, N. Y., assignorto General Electric Company, a corporation of New York ApplicationDecember 6, 1934,-Serial No.756,244

6 Claims. (c1. 62-99) My invention relates to evaporators forrefrigerating machines. i

It is an object of my invention to provide. an

evaporator for refrigerating machines having an improved arrangement forcirculating refrigerant which will provide adequate ice freezing and aircooling capacity.

Another object of my invention is to provide an evaporator including anair cooling portion providing a compartment to be cooled and a shelfarranged within the compartment which shall occupy a minimum amount ofspace and shall afford an adequate circulation of air about the shelf.

Further objects and advantages of my invention will become apparent asthe'following description proceeds, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to theaccompanying drawings in which Fig. 1 is a sectional view of a householdrefrigerator cabinet having an evaporator embodying myv invention; Fig.2 is a detailed perspective view of a portion of the evaporator andshelf construction shown in Fig. 1, and Fig. 3 is a modified form of theevaporator.

Referring now to the drawings, in Fig. 1, I

have shown a household refrigerator including a cabinet having an outermetal wall l0 provided with a partition II. A food compartment I2 isformed above the partition H by an inner metal wall or liner l3 spacedfrom the outer wall Ill and from the partition II. The space between theinner wall l3 and the wall l0 and the partition II is filled with heatinsulation l4, and the compartment I2 is provided with an insulated dooror cover IS. A refrigerant conduit I6 is associated with the wall l3 tocool the compartment 12. In the construction illustrated the conduit I6is secured in heat exchange relation to the outer surface of the wall l3and provides a passage for refrigerant uti- 5 lized to cool thecompartment l2. A refrigerated shelf I1 is secured within thecompartment to support freezing trays or the like. In order to supplyrefrigerant to the conduit IS, a motor and compressor unit is arrangedwithin acasing I'I mounted on supports i8 within the space below thepartition H. Gaseous refrigerant is compressed by the compressor withinthe casing I1 and is discharged through a connection i9 communicatingdirect y with the discharge port of the compressor and enters acondenser is described and claimed in my copending apconduit 20 securedon the inner surface of the outer wall III of the cabinet. Therefrigerant is partially liquefied within the conduit 20 and passesupwardly through a tube 2| to another condenser conduit 22 also securedto 5 L the inner surface of the outer wall it.

This condenser construction wherein the conduit is secured in heatexchange relationship to the outer wall of the refrigerator cabinet 10plication, Serial No. 554,623, filed August 3, 1931, and assigned toGeneral Electric Company, assignee of my present application.

The liquefied refrigerant condensed in the conduits 20 and 22 flowsthrough a connection 23 to a receiver or float valve chamber 24. When apredetermined amount of liquid refrigerant has been collected in thechamber 24, a float valve therein operates to discharge the liquidthrough a connection 25 to the conduit IS. The liquid refrigerant ispartially vaporized in the conduit 16 by the absorption of heat from thechamber I2, and a mixture of liquid and gaseous "refrigerant flowsthrough the end 26 of the conduit l6 and into a U-shaped tube 21'connecting one end of a passage 28 in the shelf I! with a header 29arranged within the insulation I4. The header 29 communicates with theother end of the passage 28 through a connection tube 30. The header 29is arranged so that it will maintain a level of liquid refrigerant abovethe level of the shelf i1, thereby maintaining liquid refrigerant withinthe passage 28 at all times and flooding the same. The liquid andgaseous refrigerant entering the tube 21 induce .a circulationofrefrigerant therein upwardly into the passage 28 and through the passageand the connection 30 to the header, liquid refrigerant from the headerflowing down through the other leg of the U-shaped tube 21 andrecirculating through the tube and the passage 28. The vaporizedrefrigerant collects within the header 2! and is withdrawn therefromthrough a suction conduit 3| and returns to the casing H, the interiorof the casing being at the low pressure" existing on the intake side ofthe compressor therein. L

The construction of the shelf l'! and the header 29 is clearly shown. inFig. 2. The shelf l1 comprises a single sheet of metal, one-half ofwhich is provided with indentations forming the sinuous passage 28. thetwo halves of the shelf being folded together and secured as byweldingabout the edges and between the indentations to sealthe passage.The upper half of the shelf 55 g is provided with upturned flanges 32,which are secured by bolts 33 to the inner wall 13. The

side 34 of the shelf, which is near the wall l3 is spaced therefrom inorder to afford free circulation of air about the shelf. The path ofcirculation of the refrigerant during operation of the refrigeratingmachine is indicated by ar-' pressor.

In Fig. 3 I have shown a modification in which the liquid and gaseousrefrigerant from the conduit I5 is injected into the leg of the U-shapedtube 2! which is connected to the header, thereby inducing a flow ofrefrigerant in the opposite direction through the shelf 28. When theconnections are made in this manner the passage 28 is always completelyfilled with liquid refrigerant which may be superheated by theabsorption of heat from articles placed on the shelf, but which will notbe vaporized until the pressure is released as it flows upwardly pastthe point of injection of refrigerant from the conduit l6, at whichpoint the vapor will flash out and rise to the header 29. In either ofthe modifications of my invention there is provided a rapid circulationof refrigerant through the freezing shelf l1 and an adequate freezingcapacity is insured. At the same time the conduit l6, which is arrangedon the three sides of the wall l3 other than the side on which -theshelf is mounted, provides adequate and uniform cooling of thecompartment.

From the foregoing it will readily be apparentthat I have provided animproved evaporator for refrigerating machines having a shelf whichrequires a minimum amount of space within the compartment to be cooled,and provides an adequate circulation of refrigerant for cooling the airin the compartment and for freezing purposes.

While I have shown and described my invention as applied to a householdrefrigerating machine, I do not desire my invention to be limited to theparticular construction shown and described, and I intend in theappended claims to cover all modifications within the spirit and scopeof my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A flooded evaporator for refrigerating machines including a metalwall constituting a portion of the liner of 'a compartment to be cooled,means including a refrigerant conduit secured in heat exchange relationto said wall for cooling said compartment, means including a shelfhaving a refrigerant passage therein for supporting freezing trays andthe like within said compartment, said shelf being arranged in the upperportion of said compartment and being spaced from said wall to providecirculation of air through said compartment and between said shelf andsaid wall, means including a refrigerant containing header for floodingthe passage in said shelf, means including tubes for providingcommunication between said header and both ends of the passage in saidshelf, and means providing communication between said conduit and one ofsaid tubes for inducing a circulation of refrigerant through said shelfand for producing recirculation of refrigerant through said header andsaid shelf.

2. A flooded evaporator for refrigerating machines including a metalwall constituting a portion of the liner of a compartment to be cooled,means including a refrigerant conduit secured in heat exchange relationto said wall for cooling said compartment, means including a shelfcomprising a single sheet of metal folded on itself and havingindentations therein forming a refrigerant passage for supportingfreezing trays and the like within said compartment, said shelf beingarranged in the upper portion of said compartment and being spaced fromsaid wall to provide circulation of air through said compartment andbetween said shelf and said wall, means including a refrigerantcontaining header for flooding the refrigerant passage in said shelf,means for providing communication between said header and both ends ofthe passage in said shelf, means providing communication between saidconduit and said communicating means for inducing a circulation ofrefrigerant through said shelf and for producing recirculation ofrefrigerant through said header and said shelf.

3. A flooded evaporator for refrigerating machines including a metalwall forming a compartment to be cooled, means including a refrigerantconduit secured in heat exchange relation to said wall for cooling saidcompartment, means including a shelf having a refrigerant passagetherein for supporting freezing trays and the like within saidcompartment, said shelf being arranged in the upper portion of saidcompartment and being spaced from said wall to provide circulation ofair through said compartment and between said shelf and said wall, meansincluding a refrigerant header and tubes connecting said header with thepassage in said shelf for maintaining a level of liquid refrigerantabove the level of the passage in said shelf, and means providingcommunication between said conduit and one of said tubes for inducing acirculation of refrigerant through said shelf and for producingrecirculation of refrigerant through said header and said shelf.

4. A flooded evaporator for refrigerating machines including a metalwall forming a compartment to be cooled, means including a'refrigerantpassage in heat exchange relation to said wall for cooling saidcompartment, means including a shelf having a refrigerant passagetherein for supporting freezing trays and'the like within saidcompartment, said shelf being arranged in the upper portion of saidcompartment and being spaced from said wall to provide circulation ofair through said compartment and between said shelf and said wall, meansincluding a refrigerant header and connecting said header with thepassage in said shelf for maintaining a level of liquid refrigerantabove the level of the passage in said shelf, said last men tioned meansfurther including a U-shaped passage extending downwardly from saidheader, and means providing communication between said passage in heatexchange relation with said wall and one leg of said U-shaped passageand injecting refrigerant upwardly into said one leg for producingrecirculat on of refrigerant through said header and said she f.

5. A flooded evaporator for refrigerating machines including a metalwall forming a compartment to be cooled, means including a refrigerantpassage arranged in heat exchange relation to said wall for cooling saidcompartment, means including. a shelf having a refrigerant passagetherein for supporting freezing trays and the like within saidcompartment, said shelf being arranged in the upper portion of saidcompartment and being spaced from said wall to provide circulation ofair through said compartment and between said shelf and said wall, meansincluding a refrigerant header and connecting said header with thepassage in said shelf for maintaining a level of liquid refrigerantabove the level of the passage in said shelf, and means providingcommunication between said passage in heat exchange relation with saidwall and said means connecting said header and shelf and injectingrefrigerant into said connecting means toward the passage in said shelffor inducing a rapid circulation of refrigerant through said shelf andinto said header and for producing recirculation of liquid refrigeranthrough said header and said shelf.

6. A flooded evaporator for refrigerating machines including acompartment having four metal side walls. means including a refrigerantconduit secured to three of said side walls for cooling saidcompartment, means including a shelf arranged near the fourth of saidwalls and having a refrigerant passage therein for supporting freezingtrays and the like within said compartment, said shelf being arrangednear the top of said compartment and being spaced from said fourth wallto provide circulation of air through said compartment and between saidshelf and said fourth wall, means including a header communicating withboth ends of the passage in said shelf for maintaining .a level ofliquid refrigerant above the level of said shelf, and means providingcommunication between said conduit and said shelf for inducing acirculation of refrigerant through said shelf and for producing arecirculation of refrigerant through said shelf and said header.

CHRISTIAN STEENSTRUP.

